blood sugar's effect ​on the brain

Blood Sugar’s Effects on the Brain Some of us get older faster than others. The “younger” you are when you become “old,” the more you have to look at factors other than the ravages of time for the causes of aging of the brain and body. What are the factors other than time that cause the degeneration associated with aging? Perhaps we need to look at aging and disease a little differently, and perhaps particularly with regard to the brain.

The first article in this series on Alzheimer’s listed three primary causes: inflammation; shortage of nutrients and hormones; and toxicity. These three suspects might be identified as the causes of aging, in general. (Trauma is another cause, as in the TBI – Traumatic Brain Injury - of contact sports and warfare). Now we need to look at what causes inflammation, the shortage of nutrients and hormones, and toxicity. The first red flag is the high blood sugar/insulin epidemic sweeping the nation. (We are exporting this problem successfully to the rest of the world, as well.)

The Alzheimer’s Association notes the link between Alzheimer’s disease and Type II Diabetes, or more specifically, high blood sugar. And this makes a lot of sense: High blood sugar causes inflammation and circulatory problems and toxicity, all three causes of Alzheimer’s.

What we now call Diabetes Type II was once called Adult Onset Diabetes. Because diagnoses kept occurring in younger and younger populations, the designation was changed to Type II diabetes, distinguishing it from Type I Diabetes. Type I Diabetes was originally called Juvenile Diabetes. And yes, you guessed it, the name had to be changed because diagnoses kept occurring in older populations. This is an autoimmune situation, and must be treated with insulin for life. There is nothing natural or inevitable about diabetes, short of being born without sufficient pancreatic ability.

Time alone does not age us. Genetic predisposition, lifestyle, and environment each play a role in determining the arc of aging along the timeline. Diabetes causes a wide range of physical issues, including blindness, limb amputation, kidney disease, nerve damage, and more. High blood sugar causes a host of problems, but we will see that high insulin has its own devastating effects.

Indeed, there are many references to Alzheimer’s disease as Type 3 Diabetes. The abstract of the 2008 study by Suzanne M. de la Monte (who coined the Type 3 Diabetes term) in the Journal of Diabetes Science and Technology, concludes: We conclude that the term “type 3 diabetes” accurately reflects the fact that AD represents a form of diabetes that selectively involves the brain and has molecular and biochemical features that overlap with both type 1 diabetes mellitus and T2DM. This is important because the CDC 2017 report listed 23 million people with diabetes and another 7 million undiagnosed. More disturbing is the 84 million adults, 1/3 of the adult population, with prediabetes.

​ Please note that Stop Alzheimer’s Now! By Bruce Fife, N.D., 2016, is a major resource for what follows. This is complementary to Dr. Dale E. Bredesen’s The End of Alzheimer’s.

When we eat and blood sugar begins to rise, Beta cells in the pancreas release insulin into the bloodstream until blood sugar normalizes. When blood sugar goes too low, the pancreas releases glucagon, triggering release of glucose stored in the liver.Ingestion of carbohydrates causes an immediate spike in blood sugar, but fiber, protein, and (especially) fat slow absorption so that the spike is blunted. This is why sugar and simple carbohydrates are so damaging, the spike of blood sugar, overproduction of insulin resulting in low blood sugar, and the release of glucose while hunger signals are being sent. The average non-diabetic will wake in the morning with a fasting glucose between 75-90 mg/dl (4.2-5.0 mmol/l). These fasting glucose numbers show the progression to diabetes: <90 mg/dl (<5.0 mmol/l) normal 90-100 (5.0-5.6) insulin resistance 101-125 (5.6-7.0) pre-diabetes >125 (>7.0) diabetes The risk of Alzheimer’s increases with the rise in fasting glucose.Please note that rising insulin is the first sign of a problem. Even though the pancreas is successfully holding blood sugar in the acceptable range, increasing amounts of insulin are required to maintain homeostasis. At some point, the pancreas is unable to maintain sufficient output as cells become more resistant and more insulin is required to take the glucose out of the blood.

Diabetic neuropathy (nerve damage) is the most common serious complication of diabetes. Symptoms include pain, tingling, or numbness in the extremities. Since the brain has no pain sensors, we will not feel pain, tingling, or numbness in the brain, located in the extremity called the head. Diabetics have about twice the risk of AD as non-diabetics, and the risk increases the earlier the onset of chronic high blood sugar. Insulin resistance, the inability to quickly clear excess glucose from the bloodstream, appears to play a major role in the development of Azheimer’s.

This is still a theory, but brain insulin resistance and AD appear to be influenced by the insulin resistance of the body. Oddly enough, when blood sugar rises in the body and insulin levels rise, brain levels of insulin actually fall. High blood insulin leads to low brain insulin as the blood brain barrier (BBB) becomes insulin resistant. Less insulin to the brain means less glucose to power brain cells, and neurons starved of glucose begin to die. While insulin levels are lowered in the brain, glucose enters unimpeded, and high body glucose leads to high brain glucose without sufficient brain insulin. Glucose cannot get into brain cells due to lack of insulin, so there is low brain cell glucose and high blood glucose. The high levels of sugar in the blood bond to blood proteins and fats producing inflammation, glycation, and oxidation, which trigger amyloid plaque as a defense against these toxic events. Insulin and insulin receptors in the nerve cells fall sharply early in AD. While injections of insulin to the body can readjust body glucose levels, this insulin does not cross the BBB. Are brain injections of insulin the next step? This sounds logical, but remember the law of unintended consequences.

​ Even though blood sugar/insulin issues are a strong risk factor, not every person with these issues progresses to AD, other issues such as oxidation and glycation are associated with AD, also. We will look at the diseases of the mind in the next article.​​Note:This article, like all others in these e-newsletters and website, is provided as an information resource only, and is not to be used or relied on for any diagnostic or treatment purposes. This is not a substitute for medical advice. ​If you have a health condition requiring treatment, please consult a healthcare professional.